Subject	Based on your diagnostic work (well thought out and
Posted by	SirpriZ on February 25, 2020 at 2:25 PM
	This message has been viewed 173 times.
In Reply To	Got project running, but it has low compression. Need advice posted by Polishzx on February 24, 2020 at 06:34 PM
Message	performed BTW), it sounds like #3 cylinder is the culprit of the rough idle and running, even though the compression # isn't horrible. Given that you poured oil in the cylinder and the roughness went away (and the balance test was normal), that's the only thing I can conclude. That would indicate poor sealing due to a ring, piston, or scored cylinder issue. If you have a Harbor Freight near you (or some other similar cheap tool place), you may want to purchase a cheap borescope to inspect the condition of the #3 cylinder. This may reveal cylinder scoring or gouging. If you want to try a cheaper route, you are welcome to borrow mine (just leave a $20,000 deposit ;-). The problem isn't valves, as the addition of oil wouldn't affect their sealing. If you have a stethoscope (steal one from your doctor if you don't), you may be able to locate the ticking/knocking. If it's a VTC or lifter, the noise would be up top. If it's a rod/bearing, the noise would be more evident from the oil pan area. I don't believe the rough running is a lifter due to the temporary "fix" of pouring oil in the cylinder. I also have a stethoscope that you are also welcome to borrow. Just look up my phone number in profile and text me. Good luck.
Follow Ups	Got project running, but it has low compression. Need advice - Polishzx 18:34:36 02/24/20 hard to tell in video, but sounds top end to me - Stanky (BC) 20:35:32 02/24/20 Yeah it is tough to pick up, but it is fairly loud - Polishzx 22:27:05 02/24/20 How long was it sitting for? Sounds like lifters to me - itsa300zx 21:16:01 02/24/20 Not for too long, bit over a year. - Polishzx 22:28:29 02/24/20 My opinion is its top end clatter - Cjw3 21:22:09 02/24/20 Yeah, I wasn't sure what it could be - Polishzx 22:38:27 02/24/20 You probably have a slightly bent rod from hydrolock. - Bernie (NoVA) 01:26:49 02/25/20 Would the compression go back up after putting oil in cyl? - ZXoltan 11:53:27 02/25/20 Sub 100psi is typically when you really feel a miss. (n/m) - Bernie (NoVA) 13:38:17 02/25/20 I can try again with a smaller amount of oil - Polishzx 14:01:56 02/25/20 I'll definitely try it, thanks for feedback - Polishzx 14:01:21 02/25/20 Agree. Does sound like bent rod clap. See video in comments - volcomstone550 05:53:04 02/26/20 Based on your diagnostic work (well thought out and - SirpriZ 14:25:23 02/25/20 If its a bent rod you can fix it relatively easy. - volcomstone550 05:59:54 02/26/20
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